1. Field of the Invention
This invention relates to large area (format) color displays and lighting panels that incorporate solid-state light emitters such as Light Emitting Diodes (LEDs).
2. Description of the Related Art
There are many types of light generating systems that can be used to implement large format digital color displays and other forms of entertainment lighting products. For example, one common approach is to provide a panel having an array of LEDs lights, where each “pixel” on the panel is composed of three individual red emitting, green emitting, and blue emitting LEDs. FIG. 1 illustrates an example configuration 100 of three LEDs that would be implemented on a panel as a pixel, including a red LED 104, green LED 102, and blue LED 106. Typically as indicated each LED can comprise a 10 mm LED, The overall image displayed by the panel would be configured by controlling which of the individual RGB LEDs are active at any moment in time.
However, there are numerous drawbacks with this RGB LED approach to implementing large display panels. One significant problem is that it is quite difficult to make the red and green LEDs on the panel all individually generate the exact same visual color appearance. If some of the red and green LEDs produce different shades of red or green color from other red and green LEDs, then this inconsistency in the color performance of the LEDs causes the overall panel to produce unacceptable images. This color inconsistency may be due to numerous reasons, such as differential thermal performance, and differences in required drive voltages and current of the different LEDs. Even if the panel produces consistent colors early in its usage period, it is likely that differential aging effects will cause color inconsistencies to appear later in its usage life.
Another problem with the large displays made with individual RGB LEDs is that the red, green, and blue LEDs on the panel are prominently visible as separate LED lights, especially when a viewer is located near to the panel. This causes the RGB panels to have an aesthetically unpleasing visual appearance to many viewers of the panel.
The present invention provides an approach to implement large format displays that at least in part overcomes the limitations of the known devices.